Females present reduced minimum toe clearance during walking as compared to males in active older adults

Background Physical decline due to aging has been associated with the risk of falls. Minimum toe clearance (MTC) is a gait parameter that might play a role in the mechanism of tripping and falling. However, it is unclear if there are any sex-related effects regarding MTC as people age. The present study investigated if there are sex-related differences in MTC in older active adults. Methods Twenty-three females and 23 males (F: 65.5 ± 4.8 yrs; M: 61.9 ± 5.2 yrs) walked on a treadmill at a preferred walking speed, while kinematic data were obtained at a sampling frequency of 100 Hz and up-sampled to 120 and 240Hz. MTC was calculated from the kinematics data and evaluated concerning its magnitude (i.e., MTC and MTC/leg length), the time between left/right MTC (i.e., T-MTC), amount of variability (i.e., CV and CVm), and temporal structure of variability i.e., the complexity of the time series (i.e., MTC α, T-MTC α). Results No sex effects were found for MTC/leg length, for the amount of variability (i.e., CV and CVm), and for the complexity of the time series (MTC α, T-MTC α). However, females exhibited significantly lower MTC and T-MTC after adjusting for walking speed, mass, and age as covariates. Conclusions The reduced MTC in females suggests a potential sex-related disparity in the risk of tripping and falling among active older adults.